<!DOCTYPE html>
<p>Below there should be a multicol container in vertical-lr
    writing-mode. There should be a row of columns, followed by a spanner,
    followed by another row of columns.</p>
<div style="-webkit-writing-mode:vertical-lr; line-height:2em; height:13em; background:yellow;">
    <div style="float:left; width:6em; height:6em;">
        first<br>
        first<br>
        first<br>
    </div>
    <div style="float:left; width:6em; height:1em;">
        <div style="margin:auto; width:100%; height:2px; background:black;"></div>
    </div>
    <div style="float:left; width:6em; height:6em;">
        second<br>
        second<br>
    </div>
    <div style="overflow:hidden; border:5px solid; padding:5px;">
        I am a spanner. I don't care about your precious columns.
    </div>
    <div style="float:left; width:4em; height:6em;">
        first<br>
        first<br>
    </div>
    <div style="float:left; width:4em; height:1em;">
        <div style="margin:auto; width:100%; height:2px; background:black;"></div>
    </div>
    <div style="float:left; width:4em; height:6em;">
        second<br>
    </div>
</div>
